Thermal Kinetics of Color Changes of Purple Sweet Potato Anthocyanin Pigment

자색고구마 Anthocyanin 색소의 가열에 대한 속도론적 연구

  • Lee, Lan-Sook (Department of Food Engineering, Mokpo National University) ;
  • Rhim, Jong-Whan (Department of Food Engineering, Mokpo National University)
  • 이란숙 (목포대학교 식품공학과) ;
  • 임종환 (목포대학교 식품공학과)
  • Published : 1997.06.01

Abstract

Kinetic parameters on heat-induced color changes of anthocyanin pigment from purple sweet potato were determined in the temperature range of $121{\sim}141^{\circ}C$. Color change determined by a browning index $(A_{532}\;nm/A_{420}\;nm)$ followed second order reaction kinetics. Activation energy values of purple sweet potato pigment solutions of pH 2.0, 3.0, 4.0 and 5.0 were 69.57, 76.68, 81.07 and 92.98 kJ/mol, respectively, indicating that temperature dependency of the reaction increased with pH. Apparent kinetic compensation effect between preex-ponential factor and activation energy value was observed.

Keywords

kinetics;color changes;purple sweet potato;anthocyanin